The present invention relates to a vehicle truck for supporting a ground contacting device, and in particular to an independent suspension truck which supports a wheel or wheels or a runner or ski, for example a roller skate boot has in-line wheels or tandem wheels.
Roller skates, skateboards, scooters, unicycles, wheel barrows, sleds and other weight carrying vehicles have been around for years. Each type of vehicle uses a different type of truck to steer depending on whether the device uses wheels, the number of wheels, and the configuration of the wheels, e.g. a single wheel, in-line wheels, tandem or staggered wheels. Presently no single truck exists which can perform all these functions. Some wheels may be mounted to a device which permits the wheels to turn while others have no device to actively turn the wheels, skis or blades. Most have no shock absorbing capability. Rough surfaces, rocks, cracks, etc. present hazards to in-line skates without some shock absorbing capability. Vibrations are transferred directly to the skater causing fatigue. In in-line skates, the vibration is multiplied by the number of wheels. In recent years the popularity of in-line roller skates has increased dramatically. However, these vehicles have various drawbacks, conventional in-line skates cannot be steered except by moving the entire set of wheels by applying significant force, since the wheels do not turn relative to the mounting structure. Turning on in-line skates is accomplished by slip, slide and increase or loss of friction on one or more of the wheels. The wheels turn in a single arc.
Another drawback is that most of the foregoing vehicles are not adaptable. The roller skate boot is configured to have a specific number of wheels, which are of a specified width. The boot cannot be modified to change the number of wheels or to permit an interchange with wheels of differing widths. In addition, the trucks can not be adjusted to change their shock absorbing characteristics, to alter their turning characteristics, or to resist bottoming out of the wheels against the bottom of the vehicle. Further, few if any vehicles allow for adjustment of the ride characteristics. Most vehicles cannot be reconfigured to use wheels, skis, blades or treads.
Furthermore, the trucks, or wheel supporting structures, for each particular type of vehicle are designed for use with only that type of vehicle and are not applicable to other formats. For example the trucks on an in-line roller skate can not be utilized on a scooter without significant redesign.
In view of the foregoing drawbacks it is an object of the present invention to provide a independent-suspension turnable skate vehicle truck which prevents the ground contacting portions, such as wheels) from bottoming out on the vehicle truck by providing flexible deflecting beams having one end attached to a truck axle hanger and the opposite end attached to a vehicle mounting platform. The end attached to the mounting platform is attached so that the deflecting beam part of the flexible deflecting member; meets the mounting platform at an acute angle, less than 90 degrees. The truck has a unitary construction, and may be made from plastic, graphite-like material, or other flexible material.
The deflecting beam has at least one horizontal component and/or at least one vertical component. The vertical components resist vertical deflection of the truck axle hangers to restrict upward and downward movement of the wheels or other ground contacting portions. The ability of these vertical components to resist upward and downward movement relates to the shock absorbing capability. In addition to acting as a shock absorber the vertical component also acts a center of movement for turning of the deflecting beam.
The horizontal component controls most twisting motions of the deflecting beam. As the thickness of the horizontal component is increased relative to its width, its resistance to twisting or deflection from a particular force applied to the axle hanger or mounting surface will increase. The horizontal component also acts as a dampener of side-to-side axle truck hanger wobble. The wider the horizontal component the less wobble there will be. If the horizontal deflection component is thick enough and is made of a sufficiently stiff enough material it will also act to resist vertical deflection, thereby eliminating the need for the vertical component.
The truck permits changes to the number of wheels or ground contacting portions, the position of the wheels, and the thickness of the wheels. The present invention may be converted from in-line to tandem configuration by simply changing the axles and wheels.
The unitary construction may have multiple attachment points to provide greater stability. No unitary independent suspension truck exists which provides shock absorption and prevents splaying of the wheels.
The deflection beam may have a variety of cross-sections so long as it resists vertical deflection, twist and allows for vibration absorption.
It is another object of the invention to provide a vehicle truck in which the ground contacting portions resist splaying outward under the weight of an occupant or load.
Another object of the invention to provide a vehicle truck which is adaptable for use on a skate, sled, scooter, wheel barrow, unicycle or most any other vehicle.
Yet another object of the invention is to provide a vehicle truck which can be reconfigured to change the number of, the size of, or position of ground contacting portions.
The foregoing and other objects of the present invention will be described in detail below with reference to the drawings.